I. Field of the Invention
The present invention relates to a semiconductor package and a method for fabricating the semiconductor package.
II. Description of the Prior Art
Recently, semiconductor devices have been developed to have a thinner and more miniature structure. For such semiconductor devices, there are ball grid array (BGA) semiconductor packages, chip scale semiconductor packages, and micro BGA semiconductor packages.
Also, semiconductor chips, which are mounted on semiconductor packages as mentioned above, have been developed toward a high performance of electric power circuits, an increase in operating frequency, and an expansion of circuit functions, in pace with the development of integration techniques and manufacturing equipment. For this reason, an increase in heat occurs inevitably during the operation of such a semiconductor chip.
Referring to FIG. 10, a typical BGA semiconductor package having a conventional structure involving the above mentioned problem is illustrated.
As shown in FIG. 10, the BGA semiconductor package, which is denoted by the reference numeral 100′, includes a semiconductor chip 1′ arranged at a central portion of the semiconductor package 100′. The semiconductor chip 1′ is provided with a plurality of integrated electronic circuits. A plurality of input/output pads 2′ are provided at an upper surface of the semiconductor chip 1′. A circuit board 10′ is bonded at a central portion thereof to a lower surface of the semiconductor chip 1′ by means of an adhesive 3′.
The circuit board 10′ includes a resin substrate 15′. A circuit pattern 12′ provided with bond fingers 11′ is formed on an upper surface of the resin substrate 15′ around the semiconductor chip 1′. Another circuit pattern provided with a plurality of ball lands 13′ is formed on a lower surface of the resin substrate 15′. Each of the circuit patterns is comprised of a thin film made of a conductive material such as copper (Cu). These circuit patterns are interconnected together by via holes 14′. The exposed surface portions of the circuit patterns not covered with the bond fingers 11′ and ball lands 13′ are coated with cover coats 16′, respectively, so that those circuit patterns are protected from the external environment.
The input/output pads 2′ of the semiconductor chip 1′ are connected to the bond fingers 11′ on the upper surface of the circuit board 10′ by means of conductive wires 4′, respectively. In order to protect the conductive wires 4′ from the external environment, the upper surface of the circuit board 10′ is encapsulated by a resin encapsulate 20′.
The circuit board 10′ is mounted on a mother board (not shown) in a state in which a plurality of conductive balls 40′ are fused on the ball lands 13′, respectively, so that it serves as a medium for electrical signals between the semiconductor chip 1′ and mother board.
In the BGA semiconductor package 100′ having the above mentioned configuration, the semiconductor chip 1′ thereof exchanges electrical signals with the mother board via the input/output pads 2′, conductive wires 4′, bond fingers 11′, via holes 14′, ball lands 13′, and conductive balls 40′, respectively.
However, the above mentioned conventional BGA semiconductor package is problematic in that it has an increased thickness because the semiconductor chip is bonded to the upper surface of the circuit board having a relatively large thickness. This is contrary to the recent trend toward a miniaturization and thinness. As a result, the above mentioned semiconductor package is problematic in that it cannot be applied to a variety of miniature electronic appliances such as portable phones, cellular phones, pagers, and notebooks.
Furthermore, in spite of the increasing heat generated at the semiconductor chip, as mentioned above, there is no appropriate heat discharge means in the conventional semiconductor package. As a result, the conventional semiconductor package is implicated in a heat-related degradation in the electrical performance and other functions of the semiconductor chip. In severe cases, the semiconductor package and the electronic appliance using it may be so damaged as not to be inoperable.
Although a semiconductor package has been proposed, which is provided with a heat discharge plate or heat sink for easily discharging heat generated from the semiconductor chip, the provision of such a heat discharge plate causes another problem because it serves to further increase the thickness of the semiconductor package while increasing the manufacturing costs.